PARIS -- Vivendi Universal said it has sold its remaining 9.9% stake in Havas Advertising for 453 million euros ($386.8 million) to institutional investors.

The recently merged Franco-American media group said the sale, which yielded a 113 million euros capital gain, would help finance its recent spate of U.S. acquisitions. Vivendi Universal announced last week that it would acquire publisher Houghton Mifflin Co. for $1.7 billion (2.01 billion euros), making the group the world's second-largest global educational...